Capacitors are commonly-used electrical components in semiconductor integrated circuitry, for example memory circuitry such as DRAM circuitry. A typical capacitor is comprised of two conductive electrodes separated by a non-conducting capacitor dielectric region. As integrated circuit density increases, there is a continuing challenge to maintain sufficiently high storage capacitance despite decreasing capacitor area. One way of increasing cell capacitance is through cell structure techniques. Such techniques include three-dimensional cell capacitors, such as trenched and stack capacitors. Other ways of increasing cell capacitance include the development and utilization of new materials for one or both of the electrodes and the capacitor dielectric region.
One type of capacitor utilizes a metal-insulator-metal (MIM) construction. Such can provide capacitance increase in comparison to where at least one of the capacitor electrodes is conductively doped semiconductor material. However, such capacitance increase also undesirably significantly increases leakage current across the capacitor. Further, deposition of oxide-containing capacitor dielectric materials to form a part of a capacitor dielectric region can be problematic in the fabrication of metal-containing capacitor electrodes.
Accordingly, needs remain for improved capacitor constructions and methods of forming capacitors.